Decorative films are used as wrappings on the surfaces of molded parts such as interior and exterior parts of automobiles or motorcycles, such as side cowls or center cowls, to form decorative three-dimensional molded parts. In recent years it has become common to form irregular patterns on such three-dimensional molded part surfaces in order to provide a decorative design with a three-dimensional effect. Formation of such irregular patterns on the surfaces of three-dimensional molded parts usually requires formation of irregularities on the surface of the actual base of the molded part, and therefore a molding die has been necessary for each irregular pattern.
Methods for forming three-dimensional designs on molded parts, on the other hand, include methods using films or sheets with irregularities on their surfaces, and the following publications relate to such methods.
Japanese Unexamined Patent Publication HEI No. 9-295499, published Nov. 18, 1997, describes a decorative body comprising a base and a design pattern of a desired form composed of a synthetic resin sheet formed in a fixed manner on the top of the base, and a surface material composed of a fine irregular design-bearing transparent synthetic resin sheet, formed on the design pattern in such a manner that spaces are present between the sheet and the design pattern by the shapes of the upward bulges, and with the edges fixed onto the edges of the design pattern.
Japanese Unexamined Patent Publication No. 2003-127225, published May 8, 2003, describes a process for production of a three-dimensional decorative body comprising: a melt extruded thermoplastic resin being filled into a mold material with a plurality of recesses, and the raised design sections composed of the resin filled into the recesses of the mold material being transferred to the surface of a base sheet of the heated thermoplastic resin, and fused therewith.
Japanese Unexamined Patent Publication No. 2004-42409, published Feb. 12, 2004, describes a process for production of an insert sheet, wherein a laminated body obtained by forming at least a surface protective layer composed of an uncured ionizing radiation-curable resin on one side of a transparent or semi-transparent base sheet, and a molding die having fine irregularities on the surface, are used to mold the surface protective layer side of the laminated body by heated pressing, after which the side is irradiated with ionizing radiation to harden the surface protective layer, thus providing at least a decorating layer with a design pattern on the base sheet side of the laminated body.